Figure 3.

Reducing dimensionality of physicochemical space. A, The proportion of variance in physicochemical descriptors is explained by each of the PCs (starting at ∼0.32), and the cumulative variance is explained (starting at ∼0.01). B, The five descriptors that weighted most heavily at the ends of PC1 of physicochemical space. The descriptors are as follows: sV, sum of atomic van der Waals volumes (scaled on carbon atom); Xu, Xu index; Xov, pleasantness connectivity index χ-0′; nSK, number of non-H atoms; SRW01, self-returning walk count of order 01 (number of non-H atoms, nSK); VEe2, average eigenvector coefficient sum from electronegativity weighted distance matrix; VEZ2, average eigenvector coefficient sum from z-weighted distance matrix (Barysz matrix); Vem2, average eigenvector coefficient sum from mass weighted distance matrix; VEA2, average eigenvector coefficient sum from adjacency matrix; VED2, average eigenvector coefficient sum from distance matrix.